Crimping device



July 14, 1964 D. J. LAME; 3,140,525

CRIMPING DEVICE Filed July 21, 1961 2 Sheets-Sheet l INVENTOR. DOUGLAS J. LAMB ATTORNEY July 14, 1964 LAMB 3,140,525

CRIMPING DEVICE Filed July 21, 1961 2 Sheets-Sheet 2 MWWWR DOUGLAS J-LAMB ATTOR EY United States Patent C) 3,140,525 CRIMPING DEVICE Douglas J. Lamb, Gulf Breeze, Fla., assignor, by mesne assignments, to Monsanto Company, a corporation of Delaware Filed July 21, 1961, Ser. No. 125,736 4 Claims. (Cl. 28-1) This invention relates to crimping devices and more particularly to yarn or tow crimping gears having replaceable teeth.

Conventional crimping gears used in the crimping of man-made filaments or yarn are usually milled from a solid steel blank in a manner conventional in the production of gears. One of the disadvantages of this type of crimping gear is that damage to one tooth on the gear necessitates a replacement of the complete gear. Another disadvantage of this conventional gear is that it is very difiicult to produce a gear having teeth finer than 32 dirnetral pitch and also having an adequate strength for the job. Another disadvantage of conventional. crimping equipment is that a random crimp pattern cannot be obtained. With these problems in mind it is one of the objects of this invention to provide a novel and improved crimping gear.

Another object of this invention is to provide a crimping gear having'replaceable teeth.

A further object of this invention, is, to provide a crimping gear having teeth of very small size but'of adequate strength.

It is still another object of this invention to provide a crimping gear having teeth which are rectangular in cross section.

Another object of this invention is to provide a pair of crimping gears which impart a random crimp to yarn.

Still another object of this invention is to provide a pair of crimping gears wherein spaced teeth grip the yarn to pull it across sharp teeth and thereby crimp it as the teeth mesh.

One embodiment of this invention contemplates a crimping gear which is provided with a hub having a plurality of radial slots in which fiat teeth are positioned and held by end plates. Replacement of a damaged tooth is efr'ected by removing one of the end plates and substituting a new tooth for the damaged one. Teeth of various length and cross sections can be used to obtain a random crimp pattern. Also, spaced yarn-gripping teeth can be used to pull the yarn across sharp teeth and thereby simultaneously curl and crimp it as the sharp teeth mesh.

Other objects and advantages of the invention will become apparent when the following detailed description is read in conjunction with the appended drawings, in which FIGURE 1 is a perspective view showing a pair of gear teeth which illustrate the principles of the invention being used to crimp a yarn;

FIGURE 2 is a front view, partially sectioned, of one of the gears showing the manner in which the individual teeth are held on a hub;

FIGURE 3 is an end view of a pair of crimping gears one of which is provided with teeth of uniformly varying lengths;

FIGURE 4 is a side view of a yarn crimped by the gears of FIGURE 3;

FIGURE 5 is a fragmentary end view of another embodiment of the invention showing the use of different crimping teeth, and

FIGURE 6 is a fragmentary end view of a pair of crimping gears utilizing crimping teeth having concave outer ends.

3,140,525 Patented July 14, 1964 Referring now in detail to the drawing, a pair of crimping gears 11 shown crimping a yarn 12. The gears 11 are mounted on and driven by shafts 13 which are interconnected by gears 14. The gears 11 are driven by a. motor 15 connected to one of the shafts 13. Each gear 11. is provided with a hub 16 (FIG. 2) having therein a plurality of spaced radial slots 17 which extend longitudinally along the hub. The hub 16 fits onto and is secured on the shaft 13 between a nut 18' and a pin 19 extending through the shaft 13 and having its ends positioned in. notches 20 in the hub. Each of the slots 17 receive a thin, flat elongated tooth 21 having a rectangular cross section and a pair of rectangular lugs 23 and 24 extending from the sides thereof.

A pair of end plates 27 and 28- secured to the hub 16 by bolts 29 are provided with cylindrical flanges 31 and 32, respectively, which overlap the lugs 23 and 24 to hold the teeth 21 in the slots 17 in the hub 16. A study of FIGURE 2 will show thatthe end plates 27 and 28 rigidly secure the teeth 21 in the slot 17.

In operationof the crimping gears illustrated in FIGS. 1 and 2, the yarn is passed between the meshed gears where it is uniformly crimped by the teeth 21. By making the teeth 21 of flat stock these teeth are not only very strong but also may be positioned very close together to give a very small crimp to the tow 12. Also, teeth of various radial lengths may be inserted in the slots 17 to provide a crimp which varies along the tow 12. Replacement of one tooth or a damaged tooth is effected by removing the end plate 27, removing the desired tooth from its slot 17 and replacing it with another tooth. This obviously cannot be done with a conventional crimping gear.

FIGURE 3 illustrates a pair of crimping gears wherein one of the gears has teeth of uniformly varying lengths attached thereto so that this gear is in effect eccentric. It can be seen that a yarn passed between these gears will have imparted thereto a crimp having configuration such as that illustrated in FIGURE 4. A crimp pattern such as this is desirable in the manufacture of certain fabrics.

FIGURE 5 illustrates a pair of crimping gears 35 and 36 having spaced yarn gripping teeth separated by sharpedged teeth which mesh to a greater degree than the gripping teeth, i.e., the sharp-edged teeth are longer than the yarn gripping teeth. The gear 35 has spaced, fiatfaced teeth 38 which are each covered with a thick layer 39 of rubber or some other resilient material and which are secured to the gear 35 in the manner described above. The gear 36 carries secured thereto as described above, rounded teeth 40 which cooperate with the flatfaced teeth 38 to grip the yarn 12 therebetween, the teeth 40 being spaced around the gear 36. Following the teeth 38 and 4t) (i.e., positioned between adjacent teeth 38 and 40) on each of the gears 35 and 36 are sharpened teeth 41 across which the yarn is pulled as these teeth mesh. The pulling of the yarn 12 across these sharp-edged teeth will curl the yarn in the same way that a paper strip is curled when pulled across a knife edge. The mesh or overlap of the teeth 41 imparts a crimp to the yarn 12. Thus, these gears simultaneously crimp and curl the yarn. The teeth 41 may have the sharp edges facing away from the gripping teeth 38 and 40 as shown in FIGURE 5. Several of the sharpened teeth 41 are positioned between adjacent flat-faced teeth 38 on the gear 35 and a like number are positioned between adjacent rounded teeth 40 on the gear 36.

FIGURE 6 illustrates gear teeth 44 having concave outer ends. The concavity of these outer ends in effect provides the teeth with double edges 45 and 46. These edges bite into the yarn to prevent its slippage across the teeth. The prevention of yarn slippage across the ends of the gear teeth will cause the yarn to be stretched as the gears move into mesh. Where the ends of the gear teeth are rounded or smooth, the increase in the length of the yarn path as the yarn moves into the region of mesh of the gears is accommodated for by a faster yarn feed into this regionthe yarn sliding across the smooth teeth. In the case Where the yarn cannot slide across the teeth, it is in effect held at the ends of the teeth so that it is stretched between the ends of adjacent teeth as the teeth mesh or overlap to a greater degree. Thus, the yarn will not only be crimped but will also be stretched.

To effect a random crimp, the gears may be provided with teeth having various cross sections and end configurations. Some of the teeth may be omitted from the gears to provide additional crimping variations. Also, some of the teeth may be smooth while others are roughened.

It is to be understood that the embodiment disclosed herein is merely illustrative and that this embodiment may be modified or amended and that numerous other embodiments may be contemplated without departing from the spirit and scope of the invention.

I claim:

1. An apparatus for crimping a filament, comprising a first crimping gear, a second crimping gear meshed with the first gear, said second gear having teeth which vary in length in such a manner that the pitch circle of the second gear is eccentric to the axis of said second gear, each of said gears having removable teeth, and means for driving the gears.

2. An apparatus for crimping a filament, comprising a first hub having therein a plurality of spaced radial slots, a plurality of first teeth of uniform length positioned in the slots and having at opposite sides thereof extending lugs, a pair of first end plates secured to the hub and having flanges which overlap the lugs to retain the teeth in the slots, a second hub spaced from the first hub and having therein a plurality of spaced radial slots, a plurality of teeth positioned in the slots in the second hub and having at the opposite sides thereof extending lugs, and a second pair of end plates secured to the second hub and having flanges which overlap the lugs to retain said teeth in said slots, said second teeth being of varying lengths.

3. An apparatus for crimping a filament, comprising a first hub having therein a plurality of longitudinal slots, a plurality of teeth secured in the slots in the first hub, a second hub spaced from the first hub and having therein a plurality of longitudinal slots, a plurality of second teeth mounted in the slots in the second hub, said second teeth being of varying length, and means secured to the second hub for holding the second teeth thereon.

4. An apparatus for crimping a filament, comprising a first crimping gear, a second crimping gear meshed with the first gear, said second gear having teeth being of varying length and arranged in such a manner that the pitch circle thereof defined by the teeth is eccentric to the axis of said second gear, and means for driving the gears.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN APPARATUS FOR CRIMPING A FILAMENT, COMPRISING A FIRST CRIMPING GEAR, A SECOND CRIMPING GEAR MESHED WITH THE FIRST GEAR, SAID SECOND GEAR HAVING TEETH WHICH VARY IN LENGTH IN SUCH A MANNER THAT THE PITCH CIRCLE OF THE SECOND GEAR IS ECCENTRIC TO THE AXIS OF SAID SECOND GEAR, EACH OF SAID GEARS HAVING REMOVABLE TEETH, AND MEANS FOR DRIVING THE GEARS. 